<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<HTML
><HEAD
><TITLE
>btree_gin</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK
REV="MADE"
HREF="mailto:pgsql-docs@postgresql.org"><LINK
REL="HOME"
TITLE="PostgreSQL 9.1.2 Documentation"
HREF="index.html"><LINK
REL="UP"
TITLE="Additional Supplied Modules"
HREF="contrib.html"><LINK
REL="PREVIOUS"
TITLE="auto_explain"
HREF="auto-explain.html"><LINK
REL="NEXT"
TITLE="btree_gist"
HREF="btree-gist.html"><LINK
REL="STYLESHEET"
TYPE="text/css"
HREF="stylesheet.css"><META
HTTP-EQUIV="Content-Type"
CONTENT="text/html; charset=ISO-8859-1"><META
NAME="creation"
CONTENT="2011-12-01T22:07:59"></HEAD
><BODY
CLASS="SECT1"
><DIV
CLASS="NAVHEADER"
><TABLE
SUMMARY="Header navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TH
COLSPAN="5"
ALIGN="center"
VALIGN="bottom"
><A
HREF="index.html"
>PostgreSQL 9.1.2 Documentation</A
></TH
></TR
><TR
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="top"
><A
TITLE="auto_explain"
HREF="auto-explain.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="top"
><A
HREF="contrib.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="60%"
ALIGN="center"
VALIGN="bottom"
>Appendix F. Additional Supplied Modules</TD
><TD
WIDTH="20%"
ALIGN="right"
VALIGN="top"
><A
TITLE="btree_gist"
HREF="btree-gist.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><DIV
CLASS="SECT1"
><H1
CLASS="SECT1"
><A
NAME="BTREE-GIN"
>F.4. btree_gin</A
></H1
><P
>  <TT
CLASS="FILENAME"
>btree_gin</TT
> provides sample GIN operator classes that
  implement B-tree equivalent behavior for the data types
  <TT
CLASS="TYPE"
>int2</TT
>, <TT
CLASS="TYPE"
>int4</TT
>, <TT
CLASS="TYPE"
>int8</TT
>, <TT
CLASS="TYPE"
>float4</TT
>,
  <TT
CLASS="TYPE"
>float8</TT
>, <TT
CLASS="TYPE"
>timestamp with time zone</TT
>,
  <TT
CLASS="TYPE"
>timestamp without time zone</TT
>, <TT
CLASS="TYPE"
>time with time zone</TT
>,
  <TT
CLASS="TYPE"
>time without time zone</TT
>, <TT
CLASS="TYPE"
>date</TT
>, <TT
CLASS="TYPE"
>interval</TT
>,
  <TT
CLASS="TYPE"
>oid</TT
>, <TT
CLASS="TYPE"
>money</TT
>, <TT
CLASS="TYPE"
>"char"</TT
>,
  <TT
CLASS="TYPE"
>varchar</TT
>, <TT
CLASS="TYPE"
>text</TT
>, <TT
CLASS="TYPE"
>bytea</TT
>, <TT
CLASS="TYPE"
>bit</TT
>,
  <TT
CLASS="TYPE"
>varbit</TT
>, <TT
CLASS="TYPE"
>macaddr</TT
>, <TT
CLASS="TYPE"
>inet</TT
>, and <TT
CLASS="TYPE"
>cidr</TT
>.
 </P
><P
>  In general, these operator classes will not outperform the equivalent
  standard B-tree index methods, and they lack one major feature of the
  standard B-tree code: the ability to enforce uniqueness.  However,
  they are useful for GIN testing and as a base for developing other
  GIN operator classes.  Also, for queries that test both a GIN-indexable
  column and a B-tree-indexable column, it might be more efficient to create
  a multicolumn GIN index that uses one of these operator classes than to create
  two separate indexes that would have to be combined via bitmap ANDing.
 </P
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN130286"
>F.4.1. Example Usage</A
></H2
><PRE
CLASS="PROGRAMLISTING"
>CREATE TABLE test (a int4);
-- create index
CREATE INDEX testidx ON test USING gin (a);
-- query
SELECT * FROM test WHERE a &lt; 10;</PRE
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN130289"
>F.4.2. Authors</A
></H2
><P
>   Teodor Sigaev (<CODE
CLASS="EMAIL"
>&#60;<A
HREF="mailto:teodor@stack.net"
>teodor@stack.net</A
>&#62;</CODE
>) and
   Oleg Bartunov (<CODE
CLASS="EMAIL"
>&#60;<A
HREF="mailto:oleg@sai.msu.su"
>oleg@sai.msu.su</A
>&#62;</CODE
>).  See
   <A
HREF="http://www.sai.msu.su/~megera/oddmuse/index.cgi/Gin"
TARGET="_top"
>http://www.sai.msu.su/~megera/oddmuse/index.cgi/Gin</A
>
   for additional information.
  </P
></DIV
></DIV
><DIV
CLASS="NAVFOOTER"
><HR
ALIGN="LEFT"
WIDTH="100%"><TABLE
SUMMARY="Footer navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><A
HREF="auto-explain.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="index.html"
ACCESSKEY="H"
>Home</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><A
HREF="btree-gist.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
>auto_explain</TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="contrib.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>btree_gist</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>